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Old 08-18-2010, 10:17 AM   #16
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I'm sorry but you no basis for making that statement. 14.5mm engines have dominated the Worlds & Euro Championships ever since they were introduced.
Fantini and Cristiani have setted many pole positions and several wins. But this subject can have a endless discussion and one of them is the question if Novarossi is keeping the best materials for their own teamdrivers.
As all other brands from Novarossi (Gimar and RB) have acces to the 14.5mm crankshaft and so also MAX but still they choose to use the 14mm crankshaft.

In theory and practical it is known that more mass further away from the center creates more forces preventing a fast acceleration. If you realy do take a look into it about the needed strength and the production of a crankshaft the 14.5mm has in a comercial way more advantages and in a performance way disadvantages.
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Old 08-18-2010, 11:57 AM   #17
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In theory and practical it is known that more mass further away from the center creates more forces preventing a fast acceleration. If you realy do take a look into it about the needed strength and the production of a crankshaft the 14.5mm has in a comercial way more advantages and in a performance way disadvantages.
The mass of the crankshaft wall is negligible compared to the mass of the counterweight, flywheel, clutch... The real intellectual debate on crank diameter has to do with crankcase volume, pumping efficiency and flow rates.
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Old 08-18-2010, 12:04 PM   #18
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Just confirmed by 4 of the best fluid dynamics and mechanical engineers in the world.
Jaquin is correct.
My 2 cents.
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Old 08-18-2010, 12:26 PM   #19
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Originally Posted by jdesoto View Post
The mass of the crankshaft wall is negligible compared to the mass of the counterweight, flywheel, clutch... The real intellectual debate on crank diameter has to do with crankcase volume, pumping efficiency and flow rates.
As long the hole through it has the same size the outside diameter does not have influence on the crankcase volume, flow etc.....
And there is the difference, with the 14mm crankshaft the left over material will be thin causing more flex and less strength. A more advanced (and so a more expensive) hardening methode must be used to keep the flex in a controlable range and still keeping the strength.

One other difference in the world of bearings is that smaller bearings can stand higher rpm's, with our rpm range it is not wise to go larger. And while most brands are using 25.4 x 14 as a bearing you have to come up with a new size so you do have a larger part in the aftermarket.
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Old 08-18-2010, 01:28 PM   #20
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Originally Posted by jdesoto View Post
I'm sorry but you no basis for making that statement. 14.5mm engines have dominated the Worlds & Euro Championships ever since they were introduced.
These statements your making are a little contradicting on the 14 mm crank as for it being old technology ...... My question is if it is not a contender with the 14.5 why does gi-mar offer a 14 mm version 21 which is just as expensive as the 14.5. Just curious.
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Old 08-18-2010, 01:45 PM   #21
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I dont really know but I am going to guess more pumping volume = less run time.
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Old 08-18-2010, 01:58 PM   #22
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this is getting good but think about the simple things a bigger hole has more volume and i small hole has more pressure . so think about the engine as a air pump .
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Old 08-18-2010, 02:09 PM   #23
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It's pumping both. I dont really know though. Not my area of expertise. I am curious now. I will see what the experts say on my end and get back.
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Old 08-18-2010, 02:29 PM   #24
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Go to a math teacher and ask about rotating weight of a shaft of 14mm with a 10mm hole and a 14.5mm shaft with a 10mm hole at 40.000+ rpm, he would calculate a difference of several kilograms
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Old 08-18-2010, 05:10 PM   #25
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For whats its worth i have ran both and 14mm crank gives more bottom end and i will explain why . The smaller the hole will force the fuel through faster getting up the crankcase faster therefore making power faster . The 14.5 will allow more fuel to go through but slower because less pressure therefore giving more midrange and top end . example : take a garden hose with no nozzle and turn on water , alot of water comes out but not to fast , then block off some of the water with your thumb and see how fast the water comes out , not alot but faster . I believe this is what is happening in my opinion .

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p.s. why does a 7.5 restrictor give more bottom end than a 9mm ? answer: it gets the air in faster just like the garden hose theory . this i have proved year after year. just my 2 cents no change needed . lol
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Old 08-18-2010, 05:59 PM   #26
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Quote:
Originally Posted by Roelof View Post
Fantini and Cristiani have setted many pole positions and several wins. But this subject can have a endless discussion and one of them is the question if Novarossi is keeping the best materials for their own teamdrivers.
As all other brands from Novarossi (Gimar and RB) have acces to the 14.5mm crankshaft and so also MAX but still they choose to use the 14mm crankshaft.

In theory and practical it is known that more mass further away from the center creates more forces preventing a fast acceleration. If you realy do take a look into it about the needed strength and the production of a crankshaft the 14.5mm has in a comercial way more advantages and in a performance way disadvantages.
If what your saying is correct, then 11.5mm is a cheaper/superior technology compared to 11.9mm...

Why Novarossi hasn't made any 11.5mm engines than those for other companies like Max/RB/Gimar/Capricorn???
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Old 08-18-2010, 08:00 PM   #27
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Quote:
Originally Posted by TEAM BROOKLYN View Post
For whats its worth i have ran both and 14mm crank gives more bottom end and i will explain why . The smaller the hole will force the fuel through faster getting up the crankcase faster therefore making power faster . The 14.5 will allow more fuel to go through but slower because less pressure therefore giving more midrange and top end . example : take a garden hose with no nozzle and turn on water , alot of water comes out but not to fast , then block off some of the water with your thumb and see how fast the water comes out , not alot but faster . I believe this is what is happening in my opinion .

Richard Siriano
Brooklyn Hobbies

p.s. why does a 7.5 restrictor give more bottom end than a 9mm ? answer: it gets the air in faster just like the garden hose theory . this i have proved year after year. just my 2 cents no change needed . lol
Rich do yo have a garden hose for that small patch of grass you have all you need is a bucket and the lawn is done
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Old 08-18-2010, 10:12 PM   #28
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max power is way faster than nova..

and its user friendly too
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Old 08-19-2010, 02:10 AM   #29
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[QUOTE=TEAM BROOKLYN;7824499]For whats its worth i have ran both and 14mm crank gives more bottom end and i will explain why . The smaller the hole will force the fuel through faster getting up the crankcase faster therefore making power faster . /QUOTE]

You can only know the real difference if you know the timings, materials, volumes are the same. If not, then you can not compare engines on just the acceleration.

Quote:
Originally Posted by Riketsu View Post
If what your saying is correct, then 11.5mm is a cheaper/superior technology compared to 11.9mm...

Why Novarossi hasn't made any 11.5mm engines than those for other companies like Max/RB/Gimar/Capricorn???
No, I just say a larger diameter is cheaper. Get rid of the idea that newer is better. Novarossi is a commercial comany pumping many engines a year. A faster worktime on an engine results more engines without the invest of more machines and persons working on those machines. Beside that, they must show you some changes so you think the newer engine is better.
Why others do not have the 11.9mm crank beats me but I can imagine Novarossi wants something different for themselves.
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Old 08-19-2010, 06:46 AM   #30
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[QUOTE=Roelof;7826368]
Quote:
Originally Posted by TEAM BROOKLYN View Post
For whats its worth i have ran both and 14mm crank gives more bottom end and i will explain why . The smaller the hole will force the fuel through faster getting up the crankcase faster therefore making power faster . /QUOTE]

You can only know the real difference if you know the timings, materials, volumes are the same. If not, then you can not compare engines on just the acceleration.



No, I just say a larger diameter is cheaper. Get rid of the idea that newer is better. Novarossi is a commercial comany pumping many engines a year. A faster worktime on an engine results more engines without the invest of more machines and persons working on those machines. Beside that, they must show you some changes so you think the newer engine is better.
Why others do not have the 11.9mm crank beats me but I can imagine Novarossi wants something different for themselves.
so true
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